There is a need to provide military planners and active ground forces with real time assessment imaging of an area of interest. Specifically, this would include a system for immediately determining the effectiveness of a bombing mission. Current damage assessment practice frequently requires the deployment of high value assets to collect imagery data of the effectiveness of a bombing mission or artillery fire mission. Preferably, a low cost real time option would allow immediate feedback for every mission without endangering other assets.
Current methods of obtaining damage assessments include manned reconnaissance aircraft, unmanned air vehicles, satellites, and ground forces. Unmanned air vehicles (UAV's) have been used to carry cameras that either record or relay imagery back to an operating base. The unmanned air vehicles are relatively large and expensive. There is also some concern regarding the sophisticated imaging systems onboard the UAV should it be knocked down and recovered by an opposing force. Logistics involving UAV placement is also problematic. Coordination of the flight of the UAV with the attack of the target area is required, and the target location must be within the operating/data transmission range of the UAV.
Reconnaissance aircraft provide the most common method of bomb damage assessment. They generally operate at high altitude and require clear weather to assess the target area. In essence, reconnaissance aircraft represent a very expensive long-range version of an unmanned air vehicle. Low-level reconnaissance missions are riskier. After a bombing mission, an opposing force is generally on notice that a reconnaissance mission may follow thus increasing the danger to the crew of attracting enemy fire. Moreover, low level reconnaissance missions do not allow for loiter time over the impact area unless the mission occurred over a low hazard area.
Satellites incorporating television or infrared cameras are the safest method for bomb damage assessment. However, imaging results are dependent upon good weather in target areas. There may also be a time delay in receiving the data until the satellite is in range of the target area or conversely, a mission may have to be delayed until the satellite can provide coverage. Satellites are relatively expensive to operate and target. Redirecting the imagery devices on the satellites often requires multiple layers of administrative approval.
The most dangerous method of damage assessment involves the deployment of ground forces to the impact site. While on site examination may provide the greatest detail, it is frequently impossible due to the position of existing forces. Furthermore, ground forces may not have the vantage point of viewing an entire target area. When time is of the essence, it may be impractical to delay reporting until the opposing force has cleared the impact area.
Various alternative damage assessment systems have been developed. For example, a damage assessment system utilizing an inflatable balloon strapped to a bomb is described in U.S. Pat. No. 5,537,928 and a sensor tethered to a gravity bomb is described in U.S. Pat. No. 5,432,546. Both examples however are needlessly complicated and expensive for a system that will clearly wind up either destroyed or in enemy hands. Furthermore, the tethered system has an extremely short broadcast window before impact and the helium balloon system actually produces lift which may carry the sensor away from the impact area if a guidance mechanism is not included.
To provide control, a remote control glider was proposed in U.S. Pat. No. 5,537,909 as the means for loitering above the target. The delivery vehicle was a retrofitted Tomahawk cruise missile. The glider was equipped with programmable tracking and guidance electronics as well as means for controlling the flight path. Besides the cost and complexity of the electronics package, mission success requires proper deployment and control of the glider.
Therefore, there is a need for a family of relatively inexpensive expendable sensors that provide immediate bomb damage assessment. The sensor should replace the additional assets currently involved in collecting imagery after a bombing mission. The sensor package should be inexpensive and contain technology available on the open market due to its eventual capture by an opposing force. The expendable sensor should allow for a longer loiter time in the immediate vicinity of the impending explosion for the collection and transmission of data imagery during impact, after secondary explosions and during or after debris settles on the target area. The expendable sensor should provide a data link to an operating ground station or airborne control such that risk to life and damage to high value assets is avoided. The real time transmission of data should be produced in an easily transmittable format that can quickly be interpreted. In addition to operational assessments, the sensors should be easily configured to assist in the development, operational test and evaluation of new bombs without the high cost of instrumenting a chase delivery vehicle.